A large number of actions have to be initiated and control signals produced in transmitting and receiving devices in mobile stations, and these are correlated in time with a special time pattern, which is specific to the mobile radio standard.
A number of different standards have become established in the mobile radio field in recent years, and have been developed further or will be replaced by new standards in the future. Known examples of mobile radio standards are GSM (Global System for Mobile Communication), the 8 PSK (8-Phase Shift Keying) further development of GSM which is referred to as the EDGE (Enhanced Data Services for GSM Evolution) Standard, and various standards based on the CDMA (Code Division Multiple Access) transmission method such as UMTS (Universal Mobile Telecommunication System). Another radio standard for the fourth generation is currently already being developed as the MBS (Mobile Broadband System).
The requirements for mobile stations for mobile radio are growing with the presence of different and competing standards. Mobile stations which can support two or more mobile radio systems or standards at the same time are desired. This is dependent on the mobile station being able to produce the different time patterns for the individual standards, and being able to carry out suitable event control processes based on them.
The transmission methods, for example CDMA and TDMA, for these two different mobile radio standards are based on different symbol clock frequencies, with the transmitted data normally being structured in transmission frames, which each have a predetermined length. This structure and/or length of each transmission frame in a continuous signal sequence is predetermined, and is identified by the mobile station. The mobile station has to align its time sequence control to this structure. One difficulty that occurs in this case is that different mobile radio standards use generally incommensurable time patterns, that is to say the time patterns can generally not be changed to one another by simple clock division. Particularly in cellular mobile radio systems, the mobile station also has to carry out further functions other than the transmission and reception of data, which cannot be carried out at the same time, at least during operation of only a single receiving device. By way of example, a mobile station which supports two or more mobile radio standards, in a cellular radio communications system in which the base stations in different cells transmit at different frequencies has to measure, from time to time, whether it can receive radio signals from a different base station with sufficient reception quality. To do this, the mobile station sets its receiving device to a different frequency than that frequency at which it is currently receiving data. The data is in this case sent, for example using a UMTS system, from a base station to a receiving mobile station by interrupting the transmission at predetermined times such that it is possible for the receiving mobile station to carry out other functions, such as an adjacent channel search (search for specific data packets which are transmitted from an adjacent base station) during one or more interruption phases and, in particular, also to carry out measurements. In order to avoid loss of data, the base station transmits its data in advance at a higher transmission rate than the generally constant continuous transmission rate. In order that this increased transmission rate does not lead to higher bit error rates, the transmission power is also increased during this time period in which data is being transmitted at an increased transmission rate.
The frequency with which interruption phases are repeated as well as the time duration of the interruption phases depend on the respective radio system, and also on the respective operating mode of this radio system. One disadvantage in this case is that, as the number of inserted interruption phases increases, the transmission power on the one hand becomes higher, and the transmission quality on the other hand deteriorates.